Stockholder's Equity - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended	3 Months Ended	1 Months Ended
	Mar. 01, 2014	Mar. 31, 2014	Dec. 10, 2012 Board of Directors
Schedule Of Stockholders Equity [Line Items]
Common stock repurchase authorized amount			$ 50
Common stock repurchased, shares		30,738
Common stock repurchased, value		0.9
Remaining authorized shares available for future repurchases		37.4
Sale of preferred stock	2,587,400
Convertible preferred stock dividend, rate	6.25%
Conversion rate of preferred stock	6,912,756
Convertible preferred stock, conversion date	Mar. 01, 2014
Annualized dividend on mandatory convertible preferred stock		$ 16.2